JSF ViewScope and Bean creation - jsf

I have a problem that i don't understand:
I request a new site. A site has a link that opens a dialog. The link is inside a form.
The dialog is not inside the form.
A reduced code example:
<p:outputPanel id="layout-center" >
<h:form>
<p:commandLink id="option_field_user_profile" actionListener="#{controllerBean.getBean('userProfileBean', component).init}" oncomplete="#{controllerBean.getBean('userProfileBean', component).show}" >
<h:outputText value="#{msg.mProfile}"/>
</p:commandLink>
</h:form>
</p:outputPanel>
<p:dialog header="#{userPreferencesBean.header}" widgetVar="#{userPreferencesBean.widgetVar}" appendToBody="#{userPreferencesBean.appendToBody}" resizable="#{userPreferencesBean.resizable}" id="#{userPreferencesBean.xhtmlId}" dynamic="#{userPreferencesBean.dynamic}" modal="#{userPreferencesBean.modal}" closable="#{userPreferenceBean.closable}">
<ui:include src="/WEB-INF/templates/modification/userPreferences.xhtml" />
</p:dialog>
UserPreferencesBean is in ViewScope. My problem is now that the #PostConstruct method from the UserPreferencesBean is called twice with the non-postback request i.e. the Bean is constructed twice although it should be the same view. If i move the dialog inside the form for testing purposes it is called once, like expected. But since the dialog has its own form this is not a solution, for sure.
When the site is loaded and I hit F5, the PostConstruct method is executed once.
Has somebody an idea?

This is caused because you referenced a view scoped bean property in the view build time attribute id of the <p:dialog>. If you fix the id to be static, or to reference a request or application scoped bean property instead, then your view scoped bean will behave as expected.
See also:
JSTL in JSF2 Facelets... makes sense? - for some background explanation on view build time and view render time; the id and binding attributes of UI components are evaluated during view build time.

Related

ui:repeat with a list sending right object to a p:dialog

I currently have a giant ui:repeat. Within this ui:repeat, some of the repeated objects have a url to a popup image associated with them. When someone clicks display under that particular object, I need the url to popup in a p:dialog.
<ui:repeat var="thing" value="#{bean.thingList}">
<p:commandLink value="details" onclick="miniImage.show();"
update=":#{p:component('chart')}"
action="#{bean.setCurrentImg(thing.imageUrl)}"
rendered="#{thing.includeImage}">
</p:commandLink>
</ui:repeat>
and at the bottom of the page:
<p:dialog id="chart" widgetVar="miniImage" >
<h:graphicImage value="#{bean.currentImg}"/>
</p:dialog>
And in the backing bean I tried using a simple setter and getter for currentImg.
I am a bit confused on this now and would like to accomplish this without having to submit the entire form as well. Any help is greatly appreciated.
If you're using PrimeFaces 3.3 or newer, you could just add partialSubmit="true" to the command component. You can then control the to-be-processed components in process attribute. In this particular case, just the current component (the command component itself) is sufficient, thus so process="#this":
<p:commandLink ... process="#this" partialSubmit="true" />
This way only the request parameters which are really necessary for the process will be sent.
Unrelated to the concrete problem, I suggest to use oncomplete instead of onclick to open the dialog. Otherwise the dialog is opened before update takes place and may cause poor user experience as the enduser would see the image instantly changing.

Reaching backingbean method in datatable column JSF/PrimeFaces

I am unable to reach my backing beans method when calling it in a <p:commandLink> inside a datatable column.
My commandlink works fine when put outside the datatable, but then I cannot directly pass the selected row variable.
Here is my code:
<h:form id="reviewLists" prependId="false">
<p:messages />
<p:panel header="Beoordelingen" style="margin-bottom:10px;">
<p:dataTable value="#{reviewFinderBean.employees}" var="employee" >
<p:column headerText="Medewerker" >
<h:commandLink value="#{employee.name}" action="#{reviewFinderBean.showReviewsForEmployee(employee)}" />
</p:column>
</p:dataTable>
</p:panel>
</h:form>
When checking the http requests my browser makes I see it does another post (ajax) as expected, I have tried to use prependId="false" as I thaught the generated component names might have been unresovable but that didnt help.
The ajax post is fired but somehow is never resolved to the correct backingbean method on the server
<f:setPropertyActionListener> also doesnt resolve to any property when set correctly and used in the the datatable column.
First of all, get rid of prependId="false". It makes things worse in ajax processing and updates.
In order to fix the problem, you need to rewrite the bean in such way that it returns exactly the same data model (the value behind #{reviewFinderBean.employees}") during processing the form submit as it was during displaying the form. JSF will namely re-iterate over it in order to find the associated row where the command is been invoked.
If you want to keep the bean in the request scope, then you need to recreate exactly the same datamodel in its (post)constructor. If your bean is already in the view scope, then you need to make sure that the getter method is totally free of business logic so that the data model don't potentially change.
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated - point 4

JSF pass Object to another page

I'm trying to pass an object to another site. So i have my Gallery.xhtml where I set an object as current and redirect to another page:
<h:form>
<a4j:commandButton value="Edit Skin"
action="#{helloBean.setCurrentSkin(skin)}"
onclick="window.location.href = 'resources/html/Editor.xhtml';" />
</h:form>
But when the getter on the second page is called, the current object is null again.
Is the bean generated for each page? How could I achieve this?
My Problem was that I declared my bean as #ViewScoped, but the proper Tag is #SessionScoped. This makes sure that the Bean holds its values for the whole session and not only one view.

Why does a h:commandButton fail to submit the form if it's parent is dynamically rendered?

This JSF1 code has me totally puzzled for hours. The basic setup is this page displayed with Seam2:
<h:form encType="multipart/form-data">
<rich:dataTable value="#{results}">
...
</rich:dataTable>
<h:selectOneMenu value="#{contact.type}">
<s:selectItems value="#{contactTypes}" var="t" label="#{t.label}" />
<s:convertEntity />
<a4j:support event="onchange" reRender="submitControls" />
</h:selectOneMenu>
<h:selectOneMenu value="#{template}">
<s:selectItems value="#{allTemplates}" var="t" label="#{t.label}" />
<s:convertEntity />
<a4j:support event="onchange" reRender="submitControls" />
</h:selectOneMenu>
<a4j:outputPanel id="submitControls" layout="block">
<a4j:outputPanel rendered="#{null != results and results.size gt 0 and ('ONE' == contact.type.label or template != null)}">
<h:commandButton value="submit" action="#{manager.generate}" />
</a4j:outputPanel>
<h:outputText value="Search first" rendered="#{results == null or results.size == 0}" />
<h:outputText value="Select template first" rendered="#{'ONE' == contact.type.label and template == null}" />
</a4j:outputPanel>
</h:form>
Obviously, the original page is a bit larger. What has me scratching my head is that if I don't change contact.type (leave it at a default selected by the backing bean) the form submits fine. If I switch the type to ONE this correctly renders the "Select template first" text instead of the submit control. Restoring the submit button by selecting another type re-produces the <input> BUT without the onclick handler that was there when the form was first rendered.
Now a click on the <h:commandButton> sends a request to the server but does NOT trigger the associated action. However, it now restores the onclick handler and a second click triggers a proper submit.
I'm at a loss why this is so. Any suggestions?
EDIT: moving the rendered attribute to the button results in the same behavior (even if it did work, the original panels contain more controls that share the same condition, so they do serve a purpose)
EDIT2: I've just tested that simply re-adding the "lost" onclick handler (via firebug) that gets rendered on the submit button makes the action work as intended. I'm beginning to suspect a bad interaction between richfaces and the trinidad libs also included in this project (but not used on this page).
It's a safeguard against tampered/hacked requests. Otherwise a hacker would be able to invoke actions s/he isn't allowed to invoke by just editing the sent HTTP request parameters accordingly that the non-rendered (e.g. due to missing "ADMIN" role) command button will be invoked.
You need to make sure that you prepare the same model (managed bean instance with all properties responsible holding the conditions behind rendered attribute) during the HTTP request of processing the form submit as it was during the HTTP request of displaying the form. In JSF2, this is easy achievable by placing the bean in the view scope instead of the request scope. The view scope lives as long as you're interacting with the same view. In JSF1, you'd need to grab a 3rd party framework tag like Tomahawk's <t:saveState> or RichFaces' <a4j:keepAlive> in order to simulate the JSF2 view scope.
<a4j:keepAlive beanName="results" />
The same story applies to disabled attribute by the way.
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated
JSF 1.2: How to keep request scoped managed bean alive across postbacks on same view?
I think that with the rendered attribute and anything inside you have to take care that the evaluation of it is the same on the initial request AND the submit. It may change just before the render phase but if its not the same during application invoke it will most likely ignore the action if in this phase the button would not be rendered.
As far as i remember this happend for me mostly when the rendered expression uses something like an entity attribute that will be changed during the apply request values phase already.

Modify dynamically JSF snippets by h:commandlink

I have a h:commandlink control in page1. the control uses f:ajax to call to the following h:panelgroup :
I have a h:panelgroup control in page2 (a snippet), which has a ui:include within it.
I have a h:panelgroup control in page3 (a snippet), which has a ui:include within it.
Now according to the choices made on page1, I would like to switch the snippets by clicking on the h:commandlink control.
I have a BIG problem there: it seems that only if I click twice on the commandlink, only then the snippet changes - and not on one click.
I have tried to remove the f:ajax to render the panelgroup, and still it does not work...
There are two potential causes of this problem.
The <f:ajax> is fully re-rendering another <h:form> than where it is sitting in. This way the view state of the other form will get lost which would require invoking the action on the other form twice before it really get executed.
The solution is to not re-render the other <h:form>, but only some container component in that form. E.g.
<h:form id="otherForm">
<h:panelGroup id="content">
...
<h:panelGroup>
</h:form>
with
<f:ajax render=":otherForm:content" />
When there's a rendered attribute on the <h:commandLink> or any of its parent components, then it must evaluate true during the apply request values phase of the postback request in order to get JSF to invoke the bean action associated with the <h:commandLink> during the invoke action phase of that request. Perhaps the bean is request scoped and/or some odd/illogical flow inside the bean caused that the rendered attribute is not properly been preserved.
Best is to maintain those rendered conditions in a #ViewScoped bean and let its action methods return void or null so that the bean lives as long as you're interacting with the same view. Change the rendered conditions during action methods only and not inside setters/getters or something.

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